CVE Catalog

CVE-2026-33781

MediumCVSS 6.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.17%

6th percentile - higher than 6% of all known CVEs

Summary

On Juniper Networks Junos OS EX4k and QFX5k devices configured as service-provider edge devices, with L2PT enabled on the UNI and VSTP enabled on the NNI in VXLAN scenarios, receiving VSTP BPDUs on the UNI leads to packet buffer allocation failures and the device stops passing traffic until manually restarted. Affects 24.4 releases before 24.4R2 and 25.2 releases before 25.2R1-S1 and 25.2R2.

Risk Assessment

An unauthenticated adjacent attacker can cause a complete Denial of Service (DoS) on the network device.

Recommendation

Upgrade Junos OS to 24.4R2, 25.2R1-S1, or 25.2R2. Until then, limit exposure of UNI interfaces.

Other vulnerabilities in Junos OS

See all
Original NVD description (English source)

An Improper Check for Unusual or Exceptional Conditions vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on specific EX and QFX Series devices allow an unauthenticated, adjacent attacker to cause a complete Denial of Service (DoS). On EX4k, and QFX5k platforms configured as service-provider edge devices, if L2PT is enabled on the UNI and VSTP is enabled on NNI in VXLAN scenarios, receiving VSTP BPDUs on UNI leads to packet buffer allocation failures, resulting in the device to not pass traffic anymore until it is manually recovered with a restart.This issue affects Junos OS: * 24.4 releases before 24.4R2, * 25.2 releases before 25.2R1-S1, 25.2R2. This issue does not affect Junos OS releases before 24.4R1.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS